VWA3A-derived ependyma promoter drives increased therapeutic protein secretion into the CSF

• Main Authors: Ellie M. Carrell (Author), Yong Hong Chen (Author), Paul T. Ranum (Author), Stephanie L. Coffin (Author), Larry N. Singh (Author), Luis Tecedor (Author), Megan S. Keiser (Author), Eloise Hudry (Author), Bradley T. Hyman (Author), Beverly L. Davidson (Author)
• Format: Book
• Published: Elsevier, 2023-09-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 2162-2531; 10.1016/j.omtn.2023.07.016
• Keywords: MT: Delivery Strategies; promoter; ependyma; AAV; neurodegeneration; central nervous system; Therapeutics. Pharmacology; RM1-950
• Source: Molecular Therapy: Nucleic Acids, Vol 33, Iss , Pp 296-304 (2023)

Recombinant adeno-associated viral vectors (rAAVs) are a promising strategy to treat neurodegenerative diseases because of their ability to infect non-dividing cells and confer long-term transgene expression. Despite an ever-growing library of capsid variants, widespread delivery of AAVs in the adult central nervous system remains a challenge. We have previously demonstrated successful distribution of secreted proteins by infection of the ependyma, a layer of post-mitotic epithelial cells lining the ventricles of the brain and central column of the spinal cord, and subsequent protein delivery via the cerebrospinal fluid (CSF). Here we define a functional ependyma promoter to enhance expression from this cell type. Using RNA sequencing on human autopsy samples, we identified disease- and age-independent ependyma gene signatures. Associated promoters were cloned and screened as libraries in mouse and rhesus macaque to reveal cross-species function of a human DNA-derived von Willebrand factor domain containing 3A (VWA3A) promoter. When tested in mice, our VWA3A promoter drove strong, ependyma-localized expression of eGFP and increased secreted ApoE protein levels in the CSF by 2-12× over the ubiquitous iCAG promoter.